The present invention generally pertains to viewing glasses, and more particularly to a method and apparatus for adjusting the interpupillary distance of the glasses.
Devices for adjusting the interpupillary distance of glasses are well known in the art. For example, U.S. Pat. No. 385,872 shows binocular glasses. In one embodiment a longitudinal spring and nut arrangement are utilized to adjust the width of the eye tubes. In another embodiment a hinge and pivot construction is employed.
U.S. Pat. No. 1,851,579 illustrates binocular nose glasses. Interpupillary distance adjustment is accomplished by sliding one of the binoculars in a horizontal direction.
U.S. Pat. No. 2,024,322 discloses telescoping goggles. Interpupillary distance adjustment is effected by moving the telescopes closer together or further apart and locking them in place with a screw.
U.S. Pat. No. 2,389,428 comprises a combined spectacle and telescope. Interpupillary distance adjustment is made by moving the lenses to the desired width and locking them in place with a screw.
U.S. Pat. No. 2,935,910 comprises a stereoscopic headband loupe. Lateral adjustment is provided by a turnbuckle member.
U.S. Pat. No. 3,244,072 describes an ocular and objective shutter mechanism for laterally adjustable binoculars. Lens casing are movable from a closed position where they completely envelop the central bridge, to positions where the lens casings are moved transversely outwardly to provide interpupillary distance accommodation.
U.S. Pat. No. 3,914,012 depicts a binocular body for a microscope which permits variation of interpupillary distance without compensating lenses. Variations in interpupillary distance may be accommodated by swinging the eyepiece tubes through in an arch about the optical axis of the instrument.
U.S. Pat. No. 4,284,325 is directed to an eye span adjustment mechanism for binoculars. A pair of guide rails are disposed laterally in the binocular housing. Drive rods threadably engaged with the lens barrels are movable along the guide rails to move the lens barrels back and forth in response to a knob and adjustment rod.
The present invention is directed to an improved method and apparatus for adjusting the interpupillary distance (sometimes referred to as eye span) in glasses. The glasses of the present invention can be worn at any indoor or outdoor sporting event, nature event, or in any other circumstance where binoculars would be utilized. Alternatively, with a change of lenses, the glasses can be utilized for close up magnification viewing for coin collectors, stamp enthusiast, etc.
In accordance with a preferred embodiment of the invention, a method for adjusting the interpupillary distance of viewing glasses, includes:
(a) providing viewing glasses which include:
a glasses-type frame having a right eye opening, a left eye opening, and a bridge portion disposed therebetween;
right eye opening and left eye opening each having an inner surface;
bridge portion having a vertical slotted throughway;
a right lens holder is pivotally connected to a left lens holder at a pivot axis, the right and left lens holders each having a peripheral edge;
pivot axis slidably engages the vertical slotted throughway;
right and left lens holders are shaped and dimensioned to fit into right and left eye openings respectively, wherein the peripheral edge of the right lens holder contacts the inner surface of the right eye opening, and the peripheral edge of the left lens holder contacts the inner surface of the left eye opening;
a locking mechanism for selectively (1) locking the right lens holder and the left lens holder in fixed pivoted relationship, and (2) releasing the right and left lens holders so that the right and left lens holders may freely pivot with respect to one another; and;
(b) releasing the locking mechanism;
(c) moving the pivot axis up or down in a vertical direction along slotted throughway, thereby causing the peripheral edges of the right and left lens holders to ride horizontally inwardly or outwardly along the inner surface of the right and left eye openings respectively thereby adjusting the interpupillary distance of the viewing glasses to a desired setting; and,
(d) locking the locking mechanism to retain the right and left lens holders in a fixed pivoted relationship.
In accordance with an aspect of the invention, the right and left eye openings each have a straight horizontal portion. A circular portion of the edges of the right and left lens holders rides on the straight portion, thereby keeping the center of the lens a constant height above the straight portion of the frame. This feature makes it unnecessary for a user to move the viewing glasses up or down as the interpupillary distance is changed.
In accordance with a aspect of the invention, the method further including:
in step (a) the locking mechanism further including:
the pivot axis including a sleeve which is disposed on one of the right lens holder and the left lens holder;
sleeve having a threaded rear portion;
the other of the right lens holder and the left lens holder having a hole which receives the sleeve; and,
an adjustment screw which abuts the bridge portion, passes through the sleeve, and engages the threaded rear portion.